Sheet body feeding guide structure

ABSTRACT

Guide plates of a guide structure have guide surfaces for guiding a stimulable phosphor sheet, and flocked materials are electrostatically applied to at least the guide surfaces. Coating layers are disposed in covering relation to the flocked materials. The flocked materials comprise 66 nylon, for example, and the coating layers are made of polytetrafluoroethylene.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a sheet body feeding guide structure for protecting a surface of a sheet body against damage or the like when the sheet body is fed.

2. Description of the Related Art

Heretofore, there has been employed a stimulable phosphor sheet (sheet body) which stores a part of the energy of an applied radiation and, when exposed to applied stimulating light such as visible light, emits light in proportion to the intensity of the stored energy of the radiation.

A stimulable phosphor sheet, which is stored in a cassette, for example, stores and records the radiation image information of a subject such as a human body or the like, and then is loaded into a radiation image information reading apparatus. In the radiation image information reading apparatus, the stimulable phosphor sheet is removed from the cassette and delivered to a reading unit in which stimulating light is applied to the stimulable phosphor sheet to read the recorded radiation image information therefrom. After recorded radiation image information is read, the stimulable phosphor sheet is delivered to an erasing unit, which applies erasing light to the stimulable phosphor sheet to erase remaining radiation image information therefrom. Subsequently, the stimulable phosphor sheet is returned to the cassette, which is then discharged from the radiation image information reading apparatus.

In the radiation image information reading apparatus, the stimulable phosphor sheet is fed from the cassette through a feed system including rollers and guide plates to the reading unit and the erasing unit, and then returned to the cassette. At this time, the image recording surfaces of the stimulable phosphor sheet are held in sliding contact with the guide plates and may possibly become scratched or otherwise damaged. If the image recording surfaces of the stimulable phosphor sheet are damaged, an image produced from the radiation image information that is subsequently recorded and reproduced suffers a reduction in image quality. Particularly, the presence of such damage poses a significant problem when the stimulable phosphor sheet is repeatedly used.

According to a structure disclosed in Japanese Patent Publication No. 8-29879, a guide member for guiding a stimulable phosphor sheet is provided, and a layer softer than the stimulable phosphor sheet, e.g., a damper, is mounted on a plate which makes up the guide member.

For manufacturing the guide member of the disclosed structure, the damper is applied to the plate of the guide member using a double-sided adhesive tape. However, if the plate is complex in shape and large in size, then it is considerably difficult to perform the process of applying the damper to the plate, resulting in an increased manufacturing cost and an increased number of man-hours.

SUMMARY OF THE INVENTION

It is a major object of the present invention to provide a sheet body feeding guide structure which is of a simple and economical arrangement, and which is capable of reliably preventing damage to a sheet body.

According to the present invention, there is provided a sheet body feeding guide structure having a guide member providing a guide surface for guiding a sheet body, wherein a flocked material is electrostatically applied to at least the guide surface of the guide member, and a coating layer is disposed in covering relation to the flocked material. The flocked material comprises nylon, for example, and the coating layer is made of a fluororesin such as polytetrafluoroethylene.

Further, the sheet body preferably comprises a stimulable phosphor sheet, and the flocked material and coating layer preferably are made of electrically conductive materials.

Since the flocked material is electrostatically applied to the guide member, the flocked material can easily and reliably be mounted over the entire guide surface, even if the guide member has a complex shape. The flocked material can thus be applied inexpensively and efficiently without being limited by the shape and size of the guide member.

Furthermore, inasmuch as the coating layer is disposed in covering relation to the flocked material, the flocked material is reliably prevented from being dislodged when the sheet body moves in sliding contact therewith. In addition, the coefficient of friction between the flocked material and the sheet body can be reduced, effectively increasing the slidability of the sheet body. Therefore, any undue damage to the sheet body is reduced as much as possible.

Image recording surfaces of a stimulable phosphor sheet that is used as the sheet body are protected against abrasion marks by the flocked material and the coating layer. Consequently, images that are produced from the radiation image information recorded on the stimulable phosphor sheet maintain high image quality, and hence the stimulable phosphor sheet can be used repeatedly over a long period of time.

The flocked material and the coating layer may be made of an electrically conductive material to give the guide structure itself a function of removing electrostatic charges.

The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which preferred embodiments of the present invention are shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical cross-sectional view of a radiation image information reading apparatus, which incorporates a sheet body feeding guide structure according to the present invention;

FIG. 2 is a perspective view of guide plates of the sheet body feeding guide structure;

FIG. 3 is a side elevational view of the guide plates;

FIG. 4 is a perspective view of another guide plate of the sheet body feeding guide structure; and

FIG. 5 is an enlarged fragmentary cross-sectional view of the other guide plate shown in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows in vertical cross section a radiation image information reading apparatus 50, which incorporates a sheet body feeding guide structure 10 according to the present invention. As shown in FIG. 1, the radiation image information reading apparatus 50 has an apparatus housing 52 accommodating therein cassette loaders 56 a, 56 b, 56 c, 56 d for removably loading four cassettes 54, respectively. Each of the cassettes 54 comprises a casing 60 storing therein a stimulable phosphor sheet 58 having both opposite surfaces serving as image reading surfaces, and a lid 64 for opening and closing an opening 62 defined in the casing 60. The stimulable phosphor sheet 58 has a transparent support layer for allowing recorded radiation image information to be read from its opposite surfaces.

The cassette loaders 56 a, 56 b, 56 c, 56 d have respective support bases 66 for placing the cassettes 54 respectively thereon, and respective shutters 68 that are openably and closably positioned for shielding the interior of the apparatus housing 52 against entry of ambient light. The cassette loaders 56 a, 56 b, 56 c, 56 d incorporate therein respective cassette fixing mechanisms (not shown) for fixing the cassettes 54 in position and lid opening/closing mechanisms (not shown) for opening and closing the lids 64 of the respective cassettes 54.

A sheet feeder 70 is disposed in the apparatus housing 52 inwardly of the cassette loaders 56 a, 56 b, 56 c, 56 d in alignment therewith, for removing the stimulable phosphor sheet 58 from a desired one of the cassettes 54, and for returning the stimulable phosphor sheet 58 back to the cassette 54 after recorded radiation image information is read and remaining radiation image information is erased from the stimulable phosphor sheet 58. The sheet feeder 70 has suction cups 72 for attracting and removing the stimulable phosphor sheets 58 from the cassettes 54.

Below the sheet feeder 70 are disposed an erasing unit 82 and a reading unit 84, which are connected to the sheet feeder 70 through a feed system 80. The feed system 80 has a plurality of pairs of mutually opposing rollers 86 making up a vertical feed path 88 with the reading unit 84 positioned at the lower end of the vertical feed path 88.

The reading unit 84 comprises an auxiliary scanning feed mechanism 90 for feeding a stimulable phosphor sheet 58 in an auxiliary scanning direction indicated by the arrow D, an optical system 92 for applying a laser beam L as stimulating light in a main scanning direction to the stimulable phosphor sheet 58 while it is being fed in the auxiliary scanning direction, and a light collecting system 94 for photoelectrically reading light which is emitted from the stimulable phosphor sheet 58 upon exposure to the laser beam L.

The auxiliary scanning feed mechanism 90 has first and second roller pairs 96, 98 which are rotated in synchronism with each other. The first and second roller pairs 96, 98 are movable toward and away from each other. The light collecting system 94 comprises a pair of light guides 100 a, 100 b having lower ends disposed along the position where the stimulable phosphor sheet 58 is scanned by the laser beam L, and a pair of photomultipliers 102 a, 102 b mounted respectively on upper ends of the light guides 100 a, 100 b.

A feeder 104, for upwardly feeding a stimulable phosphor sheet 58 from which recorded radiation image information has been read, is disposed downstream of the auxiliary scanning feed mechanism 90 with respect to the direction in which the stimulable phosphor sheet 58 is fed. The feeder 104 extends upwardly to an area above a power supply. 106, and an erasing feeder 108 is disposed near the power supply 106.

The erasing feeder 108 serves to retract a stimulable phosphor sheet 58 that has been fed into the area above the power supply 106, and feed the stimulable phosphor sheet 58 in a horizontal direction indicated by the arrow E along a lower surface of the erasing unit 82. The erasing unit 82 has a plurality of erasing light sources 110. The erasing feeder 108 extends horizontally beneath the erasing unit 82 and then extends upwardly where it can connect to the feed system 80.

The feed system 80 comprises a fixed guide 120 interconnecting the cassette loader 56 a and the vertical feed path 88, path switching guides 122 a, 122 b and 122 c interconnecting the cassette loaders 56 b to 56 d and the vertical feed path 88, and a joint guide 124 interconnecting the erasing feeder 108 and the vertical feed path 88.

As shown in FIGS. 2 and 3, the path switching guide 122 a comprises a rotational shaft 134 having opposite ends rotatably supported on side plates 132 a, 132 b, and four guide members 136 fixedly mounted on the rotational shaft 134. Guide rollers 138 are rotatably mounted on the respective guide members 136. The path switching guides 122 b, 122 c are identical in structure to the path switching guide 122 a, and will not be described in detail.

The guide structure 10 has a plurality of guide plates (guide members) 14 a, 14 b and a pair of guide plates (guide members) 14 c, 14 d providing guide surfaces 12 for guiding a stimulable phosphor sheet 58. The guide plates 14 a, 14 b and 14 c, 14 d are disposed in confronting relation to opposite surfaces of the stimulable phosphor sheet 58 along the vertical feed path 88 and have different shapes depending on the location where they are installed.

The guide plates 14 a, 14 b are disposed vertically in a plurality of rows facing each other across the vertical feed path 88, corresponding to the fixed guide 120 and the path switching guides 122 a, 122 b, 122 c. The guide plates 14 a are disposed closer to the cassette loaders 56 a through 56 d.

As shown in FIG. 3, a flocked material 16 a is electrostatically applied to the guide surface 12 of the guide plate 14 a by an adhesive. The flocked material 16 a comprises 66 nylon, for example, and is in the form of fibers each having a thickness of 1.5 D (denier) and a length of 0.5 mm. The flocked material 16 a is covered with a coating layer 18 a on the guide plate 14 a. The coating layer 18 a is made of polytetrafluoroethylene (PTFE), for example.

The guide plates 14 a have bent portions on vertical opposite ends thereof for preventing the stimulable phosphor sheet 58 from becoming caught on the ends of the guide plate 14 a.

The guide plates 14 b are disposed remotely from the cassette loaders 56 a through 56 d, and are of a substantially L-shaped cross section. Each guide plate 14 b has four clearance recesses 20 defined therein at positions where the respective guide members 136 are angularly movable. A flocked material 16 b is electrostatically applied to the vertical guide surface 12 of each guide plate 14 b by an adhesive. The flocked material 16 b and flocked materials 16 c, 16 d to be described below are identical to the flocked material 16 a and will not be described in detail.

The flocked material 16 b is covered with a coating layer 18 b on the guide plate 14 b. The coating layer 18 b is made of polytetrafluoroethylene, for example. Vertical opposite ends of the guide plate 14 b are bent for preventing the stimulable phosphor sheet 58 from becoming caught on the ends of the guide plate 14 b.

The guide plates 14 c, 14 d are disposed in facing relation to each other across the vertical feed path 88 upwardly of the joint guide 124. As shown in FIGS. 4 and 5, the guide plates 14 c, 14 d are of a substantially L-shaped cross section. Each guide plate 14 c, 14 d has four openings 22 for avoiding interference with the roller pair 86.

Flocked materials 16 c, 16 d are electrostatically applied to vertical guide surfaces 12 of the guide plates 14 c, 14 d by an adhesive, and extend to boundary regions between the vertical guide surfaces 12 and upper horizontal surfaces thereof. The flocked materials 16 c, 16 d are covered with respective coating layers 18 c, 18 d on the guide plates 14 c, 14 d. The coating layers 18 c, 18 d are made of polytetrafluoroethylene, for example. Vertical opposite ends of the guide plates 14 c, 14 d are bent for preventing the stimulable phosphor sheet 58 from becoming caught on the ends of the guide plates 14 c, 14 d.

In addition to the feed system 80, the guide structure 10 also is provided in the feeder 104 and in the erasing feeder 108. Specifically, at least all those areas within the apparatus housing 52 that are held in sliding contact with stimulable phosphor sheets 58 are combined with an electrostatically applied flocked material, which is covered with a coating layer.

Operation of the radiation image information reading apparatus 50, in relation to the guide structure 10 according to the above embodiment, will be described below.

First, as shown in FIG. 1, cassettes 54 storing stimulable phosphor sheets 58 respectively therein, which contain images of desired regions of subjects such as patients recorded by an unillustrated X-ray imaging system, are loaded into the cassette loaders 56 a, 56 b, 56 c, 56 d. For removing a stimulable phosphor sheet 58 from among each of the cassettes 54 in the cassette loaders 56 a, 56 b, 56 c, 56 d, for example, from a cassette 54 in the cassette loader 56 a, the lid 64 of that cassette 54 is opened. The sheet feeder 70 operates to remove the stimulable phosphor sheet 58 from the cassette 54 and transfer the stimulable phosphor sheet 58 to the feed system 80.

The stimulable phosphor sheet 58 is fed downwardly by the feed system 80, and thereafter is supplied to the auxiliary scanning feed mechanism 90. In the auxiliary scanning feed mechanism 90, the first and second roller pairs 96, 98 are rotated to feed the stimulable phosphor sheet 58 in the auxiliary scanning direction indicated by the arrow D, while at the same time the laser beam L emitted from the optical system 92 and deflected in the main scanning direction is applied to the stimulable phosphor sheet 58, for thereby reading the radiation image information recorded on the stimulable phosphor sheet 58.

After the radiation image information is read from the stimulable phosphor sheet 58, the stimulable phosphor sheet 58 is fed upwardly of the erasing unit 82 by the feeder 104 and delivered to a horizontal position above the power supply 106. The stimulable phosphor sheet 58 is then fed horizontally in the direction indicated by the arrow E (see FIG. 1) along the lower surface of the erasing unit 82 by the erasing feeder 108, during which time remaining radiation image information is erased by the erasing light source 110.

The stimulable phosphor sheet 58 from which the remaining radiation image information has been erased is transferred from the erasing feeder 108 to the feed system 80, which then feeds the stimulable phosphor sheet 58 to the sheet feeder 70. The sheet feeder 70 returns the received stimulable phosphor sheet 58 to the cassette 54 in the cassette loader 56 a. Then, the lid 64 of the cassette 54 is closed, after which the operator removes the cassette 54 storing the stimulable phosphor sheet 58 therein from the cassette loader 56 a.

In the present embodiment, the guide structure 10 comprises guide plates 14 a through 14 d, flocked materials 16 a through 16 d that are electrostatically applied to at least the guide surfaces 12 of the guide plates 14 a through 14 d, and coating layers 18 a through 18 d, which are disposed for covering the flocked materials 16 a through 16 d.

When a stimulable phosphor sheet 58 that has been removed from the cassette 54 in the cassette loader 56 a is fed via the vertical feed path 88 to the reading unit 84, and also when the stimulable phosphor sheet 58 from which recorded radiation image information has been read is returned from the erasing feeder 108 via the vertical feed path 88 to the cassette 54, opposite surfaces of the stimulable phosphor sheet 58 are kept in contact with the flocked materials 16 a through 16 d.

Therefore, the stimulable phosphor sheet 58 is not brought into direct contact with the guide plates 14 a through 14 d. Rather, the image recording surfaces of the stimulable phosphor sheet 58 are reliably protected against abrasion marks by the flocked materials 16 a through 16 d. Consequently, images that are produced from the radiation image information recorded on the stimulable phosphor sheet 58 maintain high image quality, and hence the stimulable phosphor sheet 58 can be used repeatedly over a long period of time.

Since the flocked materials 16 a through 16 d are electrostatically applied to the guide plates 14 a through 14 d, the flocked materials 16 a through 16 d can easily and reliably be mounted over the entirety of the guide surfaces 12, even if the guide plates 14 a through 14 d have a complex shape. The flocked materials 16 a through 16 d can thus be applied inexpensively and efficiently without being limited by the shape and size of the guide plates 14 a through 14 d.

Inasmuch as the coating layers 18 a through 18 d are disposed in covering relation to the flocked materials 16 a through 16 d, the flocked materials 16 a through 16 d are reliably prevented from being dislodged when the stimulable phosphor sheet 58 moves in sliding contact therewith. The coefficient of friction between the flocked materials 16 a through 16 d and the stimulable phosphor sheet 58 is relatively small, effectively increasing the slidability of the stimulable phosphor sheet 58. Therefore, any undue damage to the stimulable phosphor sheet 58 is reduced as much as possible with a simple arrangement.

The flocked materials 16 a through 16 d may comprise electrically conductive piles, and the coating layers 18 a through 18 d may be made of an electrically conductive material, to impart to the guide structure 10 itself a function for removing electrostatic charges.

Although a certain preferred embodiment of the present invention has been shown and described in detail, it should be understood that various changes and modifications may be made therein without departing from the scope of the appended claims. 

1. A sheet body feeding guide structure for protecting a surface of a sheet body against damage when the sheet body is fed, comprising: a guide member providing a guide surface for guiding said sheet body; a flocked material electrostatically applied to at least said guide surface of the guide member; and a coating layer disposed in covering relation to said flocked material.
 2. A sheet body feeding guide structure according to claim 1, wherein said guide member has portions bent in a direction away from said sheet body, at respective ends thereof with respect to a direction in which said sheet body is fed.
 3. A sheet body feeding guide structure according to claim 1, wherein said guide member comprises a plurality of guide members having respective guide surfaces, said guide members being arranged along a direction in which said sheet body is fed, with said guide surfaces facing opposite surfaces of said sheet body.
 4. A sheet body feeding guide structure according to claim 1, wherein said sheet body comprises a stimulable phosphor sheet.
 5. A sheet body feeding guide structure according to claim 1, wherein said flocked material and said coating layer are made of an electrically conductive material. 